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Re: [TenTec] Doorknobs needed - Was: Ig drift on amps

To: <Gary@doctorgary.net>, "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] Doorknobs needed - Was: Ig drift on amps
From: "Ron Castro" <ronc@sonic.net>
Reply-to: Ron Castro <ronc@sonic.net>, Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Mon, 9 Feb 2009 20:58:30 -0800
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
*All* of them are from overseas, from what I can tell!  If you want 
originals, have you tried calling Ten Tec?  Like others, I have found the 
prices at Surplus Sales of Nebraska to border on outrageous, although 
sometimes they are the only source I can find.

My big concern about using the original components is that they didn't hold 
up in the environment you use the amp in, so you might change them out and 
then have the same problem.

         Ron  N6IE
      www.N6IE.com

----- Original Message ----- 
From: "Gary Smith" <Gary@doctorgary.net>
To: <Tentec@contesting.com>
Sent: Monday, February 09, 2009 8:17 PM
Subject: Re: [TenTec] Doorknobs needed - Was: Ig drift on amps


> Hi Ron,
>
> That was the second place I went to find them, the first was my box
> of amp parts (or what's left of it). I'm looking for the proper pf
> values but I want to replace what's there with proper sizes so I
> don't have to re-drill. I didn't see pf or size matches on Ebay for
> what came in the amp. I'm adverse to replacing much that wasn't part
> of the original design. Someday I'll sell the amp and I want to have
> the next person know it's got the expected components in it.
>
> If this was a homebrew amp, I'd make room and change the padder pf
> values to make it work.
>
> They are good prices though it looks like a lot of them are overseas.
>
> Gary
> KA1J
>
>> Gary:  Do a search on e-bay for "doorknob capacitors" and you'll two 
>> pages
>> of 'em!  The 16 kV Russian military caps are what I used in my TT 238 
>> tuner
>> mod, and they seem to be every bit as good as their US equivalents.   The
>> seller claims they were used in 12 kW antenna tuners and have 30 MHz 
>> current
>> rating of 15 Amps.  At 5 for $19.50 you can't go wrong!
>>
>>          Ron  N6IE
>>       www.N6IE.com
>>
>> ----- Original Message ----- 
>> From: "Gary Smith" <Gary@doctorgary.net>
>> To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
>> Sent: Monday, February 09, 2009 5:29 PM
>> Subject: [TenTec] Doorknobs needed - Was: Ig drift on amps
>>
>>
>> > It appears I likely need to replace at least some of the padding
>> > capacitors in the tank on my 425 to stop the Ig drift on the lower
>> > bands. To do a clean sweep, what I need to replace are the following.
>> >
>> > A. (C6, C7) Two 1000pf @ 5KV series 858s doorknobs
>> >
>> > B. (C17)     One 500pf @ 5KV series 858s doorknob
>> >
>> > C. (C18, C20) Two 300pf @ 5KV series 858s doorknobs
>> >
>> > D. (C15)     One 400pf @ 15K Series HEC HT57 doorknob
>> >
>> > E. ( C16) One 270pf @ 2KV disc: Ceramic?/Mica? which is about
>> > 1"x3/32" and is glossy yellow. On the side it reads:
>> >
>> > RMC   270    J
>> > 2KV    P     3
>> >
>> >
>> > I would like to change "E" to an 858 series doorknob, making it a
>> > 270pf @ 5KV series 858 doorknob.
>> >
>> > The Drifting Ig issue is really a problem on the low bands and I'm
>> > concerned about damaging the tubes. If you have any of these caps in
>> > as new condition available, please contact me off list.
>> >
>> > Thanks!
>> >
>> > Gary
>> > KA1J
>> > _______________________________________________
>> > TenTec mailing list
>> > TenTec@contesting.com
>> > http://lists.contesting.com/mailman/listinfo/tentec
>> >
>>
>>
>
>
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> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
> 

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